In my experience the 97 can cover you up to 7.8 and even the 8.4.
If you want to make the correct jump i suggest the 117 wide for 8.4 to 9.6.
The 107 is the best board in the line right now if you dont want to go to the 117 wide. The 107 handles everything up to a 9m sail if you want but since you have a 97 i suggest the 117w.